Internal coolant leak - How to access damage.

[tome30]

Hello, I haven't been here for a while as I haven't had a retro for a while.
I just bought a Mazda 323 1987 BF 1.5 GLX for £100
It's the first time I've had a car that I can work on fully as I have a daily ride, and a garage now!!!
It has a coolant leak that I sourced to the exhaust manifold and on removal it appears to be coming from one of the cylinders (bad news)
The oil is mayonnaise and when draining the oil at least half pint of water came out first. I have not started or driven the car (I towed it back) but I would like to know methodically what damage I need to look out for to access whether or not I should continue to try to fix it.

The idea with the car was that it is so cheap and essentially not needed, that I can, for the first time strip and engine down and try to rebuild it, without worrying too much if I succeed or not. Though I'd love to.

Engine replacement is not a choice or a wish.

Pics to follow.

Thank you all.

[tome30]

The water comes from the left most cylinder when engine is off and I fill water through the radiator filler cap.

[colnerov]

Hi, where is the water coming from, the spark plug hole or the exhaust port?

Colin

[tome30]

Exhaust port.

[colnerov]

Hi, I think I know what it is, but to confirm turn the engine over so that piston is on top dead centre and both valves are closed. At the moment the exhaust valve looks to be open. Put some more water in and see where it comes from, if it comes out out of the spark plug hole then it is probably the head gasket. If it still comes out of the exhaust port it maybe a cracked or corroded head. Removal of the head will be needed to progress from there.

Colin

[bortaf]

I'd say your gonna need to remove the head and check the gasket, so you need a head set at least, maybe a head skim (alloy heads don't like overheating) and a head rebuild.

[tome30]

Thanks for the advise, though I'm working a lot so don't expect a quick responce.

[tdipd]

It definitely has the symptoms of blown head gasket, and/or a warped and cracked head. Either way, the heads coming off to see if its repairable.

You should also investigate to find if there's a reason for the blown head/gasket other than corrosion of the gasket. check water pump is not seized or leaking, and has its blades intact. check for leaking or blocked radiator, heater matrix, or pipework too. and check the thermostat works by chuckin it in a jug of boiling water




best case scenario would be a blown gasket where the head did not overheat and therefore warp. You'd get away with a skim or sand the head, and a new gasket set.

If the head is warped, a machine shop would need to skim at best case, if its warped badly it may have thrown the valve seats oval too, meaning cut new seats, lap valves. Or is its warped really badly, chuck it in the bin.

If its cracked, you could get the machine shop to attempt a weld and machine it smooth. ... but is it really worth the cost of any of these fixes?

If your not sure if the head is warped, cracked, or even porous (in some cases) the machine shop can 'pressure test' it

if any of the above are found it'd likely be cheaper to drop in another engine or at east buy a second hand head.

[tome30]

Well I'm no expert and this is my first time, but I have a feeling the gasket blew.
Now the sludge is wiped off the pistons it doesn't appear that there is any damage to them or the walls, the head has no cracks and isn't warped.
What next, I need to clean the faces of both the head and block and will be refitting all gaskets. I want to also get the sump off, to clean out all the mayonaise.
Q's...
The cam chain sprocket came off with relative ease without removing the chain tensioner, is this something I should think about when refitting?
Which holes carry what fluid? I'd like to flush them through as they are cruddy.
What is that caked on the exhaust things (I don't know what they are called) Is it soot? How do I get it off?
Thanks

[tdipd]

That is most definitely a blown gasket haha. have you turned the engine over to check if there's damage to the bores or cylinder 1?

You check the deck of the block using brake/parts cleaner and a scraper or stanley blade, being careful not to leave deep gouges anywhere. I use a hoover right alongside it to suck up any debris scraped off.

You need to check if the head is warped, its too difficult to see by eye.
Clean the underside of the head using the scraper too, beware aluminium is very soft, do not take out gouges!

its best to have a length of flat steel stock that has a machined flat edge, you set this across the head and attempt to pass feeler gauges under it.
I presume you don't have the steel stock... I have in the past used a steel rule, but its never totally accurate.

If you are in anyway unsure, pop down to your engine builders and ask them to check, they can tell and show you in no time, and often cost nothing or little.

If it is warped you get them to skim it for about £40

If it is not warped, you can get away with using a sanding block and some 240grit paper, then 400grit to smooth the head if you think it needs it. Being careful not to make it uneven! .... if you don't feel confident with that, get it skimmed, it will come back like a mirror!

Its a carbon build up on the valves, try brake cleaner and light chips from a screwdriver. Its never going to be a performance machine so its not a big worry.


on the deck, look down the holes with a torch, any that have orange rust will be the water/coolant ones. Oil holes are usually at either end of the head.



with regards to your tensioner, i dunno how it works on that engine, so cant help you there, but on mercs its the last thing to go on as it has a build in ratcheting system.


get a new head gasket set, check your radiator for leaks, check water pump, and likely replace, check your thermostat works and coolant tank lid should be replaced.

you need to rinse out your rad and heater and all pipework by running a hose through each in both directions.

[tdipd]

PS, there is nothing more annoying than building the whole thing up again only to find out there's no compression due to a bent head. Make certain its flat! otherwise start again and chuck out that gasket!

And a big issue, I didn't do this one time an fecked it up... clean out the head bolt holes!
any oil down a hole will hydrolock and make the headbolt appear as if its torqued when it infact is not.
I not use blowgun down the hole to blow out debris, then wd40, then brake cleaner, then blowgun again. Stand clear when using blowgun, curse word comes out like a fountain!

[welshpug]

bore on 2nd in looks toast, that's had water in here standing for a very long time.

[tome30]

I put a steel rule across and it seemed straight, I'll try with feeler gauges too. No2 didn't actually look too bad once wiped clean, is it a problem for a car I'm just wanting to work for another year or so? I'll also check the other bore holes, is it ok to turn the engine back and forth now?
Thanks for all your help and again sorry if I go quiet occasionally.

[tome30]

A bit of progress, and also a big step back.

I got the engine all back together, but as I was tightening the thermostat housing on, I didn't realise that the thermostat had slipped down and I cracked the housing. A new one is on its way.

I have however started the engine and driven out of the garage and back in again. Sounds and looks good, no leaking of oil or water (apart from the cracked t'stat house)

So a happy bunny all-round, decided then to investigate the rust further.....well that's a whole other thread, not for here.

But here retrorides.proboards.com/thread/181567/fabricating-sheet-metal-fill-holes